1. Field of the Invention
The present invention relates to the field of high voltage integrated circuits, and more particularly, to a high voltage integrated circuit including a bipolar transistor within high voltage island area.
2. Description of the Related Art
High voltage integrated circuits (HVIC) provide many advantages to power control systems such as electronic ballasts, switch power supplies, and motor drives. A high voltage integrated circuit typically includes a high voltage portion, a low voltage portion and a junction termination between the high voltage portion and the low voltage portion. The junction termination, which is an area for isolation between the high voltage portion and the low voltage portion, must have a sufficiently large width to ensure the reliability of high voltage integrated circuits.
In particular, the width of the isolation area between power semiconductor devices must be maximal in order to obtain a sufficiently high breakdown voltage (e.g., 600V or greater) and prevent punch-through due to the extension of depletion regions. Because of this restriction on the width of the isolation area, only CMOS process rather than BiCMOS process has been used in the manufacture of high voltage integrated circuits.